You are here

Log in or register to post comments
Jan Vigne
Jan Vigne's picture
Offline
Last seen: Never ago
Joined: Mar 18 2006 - 12:57pm
Two channel Dolby Digital

In RR's review of the Infinity Primus P162 he states his set up for home theater includes only two front speakers. He sites several reasons for choosing this set up including this, "Second, I don't see the need for a center channel speaker, provided the main L/R speakers have broad horizontal dispersion. Finally, I don't find that bass needs to be "managed" by a separate low-frequency channel. I've found that the home thater experience can be very satisfying in a two channel set up, provided the stereo pair of speakers can sufficiently reproduce convincing home theater bass with a sense of high level dynamic drama without compression." (p. 185) Later he admits to watching an HBO series, I assume broadcast in DD, at levels which forced his wife to ask him to turn down the volume. (p.187)

The question has been raised (and from what I understand the answer is in Dolby's white paper on the DD format) regarding the midnight mode of compression when the 5.1 original soundtrack is downmixed to anything less than 5.1 speakers. Apparently, when speakers are removed from the 5.1 mix, particularly the center channel, the DD format automatically engages the midnight mode compession which will apply as much as 15dB of compression to the signal. By playing the HBO broadcast's soundtrack with high compression at high volume levels, is it possible this is the reason RR's wife found the SPL's so annoying? In other words, it was not the dynamic capbility of the Infinities which annoyed her but rather the lack of dynamics and the overall higher level of everything.

http://www.hometheatershack.com/forums/h....html#post11862

Scroll down to; September 14th, 2006, 5:31 PM.

RGibran
RGibran's picture
Offline
Last seen: 2 years 2 days ago
Joined: Oct 11 2005 - 5:50pm
Re: Two channel Dolby Digital

Sure it's possible Jan, but why don't you just get to the point and spit out your tongue?

RG

Jan Vigne
Jan Vigne's picture
Offline
Last seen: Never ago
Joined: Mar 18 2006 - 12:57pm
Re: Two channel Dolby Digital

The point should be obvious. RR's positive review of the Infinities praises their dynamic capabilities, in part due to his experience while listening to a Dolby Digital soundtrack played in midnight mode compression. While there appears to be more than sufficient reason to find the speaker's performance appealling in other areas, RR's reasoning regarding two channel DD is flawed. There can be all sorts of reasons for limiting your ht system to only two speakers but RR's argument for this set up should not be taken to heart by anyone desiring the broadest dynamic range and, one could conclude, the "best" ht experience. I think it fair to say most of us would not willfully choose to listen to our ht systems in a permanently compressed state. It should be noted that downmixing the 5.1 tracks to anything less than 5.1 speakers will result in exactly that. That is my point.

I'm not saying RR's review of the product should be devalued for this reason, only that his "advice" regarding ht set up has consequences most people do not realize. The information is not well known among audio/video salespeople and not widely disseminated by the press. I doubt the issue will affect the majority of Stereophile readers today but with the upcoming switch to digital broadcasts and DD soundtracks it might be information worth knowing and passing along to friends.

I intentionally did not title this thread "Infinity Primus 162" since my point is not about the product itself. My point has to do with the (mis)use of DD and its implications to the listener. And, by the way, this compression when downmixing is not a problem with DTS material.

  • X
    Enter your Stereophile.com username.
    Enter the password that accompanies your username.
    Loading